The reason that they do this is twofold, one, because we allow it. Were we to stand up and tell them to STFU about "undocumented immigrants", they just MIGHT listen. However, it would have to be America, as a whole. Secondly, they have no other valid argument, so they pull this PC crap. It demeans the opposition and it's an attempt to make the opposition "look bad", when in reality, all people want, in general, is fairness. It's not very fair that these people overstay their visas or come here illegally and take away our jobs, suck the system that us law abiding citizens have paid so much into, dry. IMO, it's pretty bad when we can't/ wont take care of our own citizens and yet, illegals seem to obtain "special rights & privileges".